The interaction between a publisher and a subscriber is a necessary feature in a message publication environment. In such an environment, a publisher routes messages to a subscriber through a persistent and dynamic storage center. This center, which may be thought of as a message data store, a subscription store, and a middle man between the two components, incorporates a designated storage queue for each subscriber of the system.
In a typical message publication environment, when the publisher possesses a message to be published, a publishing component contacts the subscription store to identify the potential subscribers to receive the message. Once a list of subscribers for the message to be published is obtained, the message is pushed into the designated queue of each subscriber. In order for each subscriber to receive the message, a polling mechanism is employed. Specifically, a message receiving component pulls the message from the storage queues and delivers the message to each subscriber. After the message has been received and processed by a subscriber, it is removed from that subscriber's storage queue.
The message delivery process outlined above incurs several latencies throughout the course of evaluating, sending, delivering, and removing a message. Time Te is the evaluation time and occurs at the beginning of the process after the publication interface has been provided with a message to be published. Te is the amount of time necessary to consult the subscription store in order to review and obtain a list of subscribers who can receive the message. The next encountered latency is time Tq, the queue time that is required to push the message to the queue of each subscriber identified on the subscriber list. Tp, the poll time, is the latency incurred when the receiving component polls the subscriber's queue and takes the message out to be published and processed. An additional latency component in the message delivery process, Tc, the clean-up time, occurs during the clean-up process in which the message is removed from the subscriber's queue. This latency occurs after the message has safely been polled to the subscriber and the subscriber has completely processed the message.
Generally, the latency components discussed above are not desirable. Accordingly, there is a need for systems and methods that reduce, or even eliminate entirely, one or more of the latency components involved in the transmission and publication of a message in a publisher-subscriber model. The present invention satisfies this need.